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United States Patent |
5,677,027
|
Masuda
,   et al.
|
October 14, 1997
|
Sound insulating structure
Abstract
The disclosure relates to a sound insulating structure formed on an
automobile floor panel on which at least one of a vibration and a sound is
incident. This structure includes a covering layer for covering the panel
and a cushioning layer for reducing an impact of the at least one of the
vibration and the sound. This cushioning layer is interposed between the
covering layer and the panel and made of a nonwoven fabric. This nonwoven
fabric includes 5-95 wt % of a first fiber and 5-95% of a second fiber,
wherein the total amount of the first and second fibers is 100 wt %. This
first fiber has a fineness within a range from 1.5 to 40 deniers, a first
melting point, and a first portion including polyethylene terephthalate.
The second fiber has a fineness within a range from 1.5 to 15 deniers, a
core portion, and a sheath portion covering the core portion. A majority
of the core portion includes polyethylene terephthalate. The sheath
portion includes an elastic copolyester which has a second melting point
that is lower than the first melting point and is not higher than
200.degree. C. The elastic copolyester is prepared by copolymerizing
polyethylene terephthalate and at least one other monomer. The sound
insulating structure has a high sound-transmission-loss factor within a
so-called road-noise frequency range and an adequate cushioning effect and
is particularly superior in sound insulating at a normal temperature
(15.degree.-40.degree. C.).
Inventors:
|
Masuda; Yuugorou (Takatsuki, JP);
Oku; Shousuke (Osaka, JP);
Ito; Masashi (Yokosuka, JP);
Ito; Tomohiro (Tokyo, JP);
Sugawara; Hiroshi (Yokosuka, JP)
|
Assignee:
|
Nissan Motor Co., Ltd. (Yokohama, JP);
Kanebo Ltd. (Osaka, JP)
|
Appl. No.:
|
584278 |
Filed:
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January 11, 1996 |
Foreign Application Priority Data
Current U.S. Class: |
428/96; 428/95; 442/364; 442/378 |
Intern'l Class: |
B32B 003/02 |
Field of Search: |
428/284,286,288,95,96
442/364,378
|
References Cited
U.S. Patent Documents
4840832 | Jun., 1989 | Weinle et al. | 428/156.
|
Foreign Patent Documents |
3-176241 | Jul., 1991 | JP.
| |
7-223478 | Aug., 1995 | JP.
| |
Primary Examiner: Raimund; Christopher
Attorney, Agent or Firm: Foley & Lardner
Claims
What is claimed is:
1. A sound insulating structure found on a steel automobile floor panel on
which at least one of a vibration and a sound is incident, said structure
comprising:
a covering layer of carpet for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
5-95 wt % of a second fiber having a fineness within a range from 1.5 to 15
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total of said first and second fibers being 100 wt %.
2. A structure according to claim 1, wherein said nonwoven fabric comprises
20-80 wt % of said first fiber and 20-80 wt % of said second fiber.
3. A structure according to claim 1, wherein said elastic copolyester has a
tan .delta. of at least 0.1 at a temperature within a range from
15.degree. to 40.degree. C., said tan .delta. being a ratio of a loss
elasticity of said elastic copolyester to a storage modulus of said
elastic copolyester, and wherein said first and second fibers are bonded
together by fusing said elastic copolyester.
4. A structure according to claim 1, wherein said first fiber is a
conjugated fiber having an inside which is free of a hollow space.
5. A structure according to claim 1, further comprising a backing layer for
backing therewith said covering layer, said backing layer being interposed
between said covering layer and said cushioning layer and comprising a
thermoplastic resin.
6. A structure according to claim 1, wherein said cushioning layer has a
hardness such that said cushioning layer is compressed by 25% when said
cushioning layer receives a load ranging from 4 to 60 kgf.
7. A structure according to claim 1, wherein said cushioning layer has a
thickness within a range from 2 to 50 mm.
8. A structure according to claim 1, wherein said nonwoven fabric has an
apparent density within a range from 0.03 to 0.1 g/cm.sup.3.
9. A structure according to claim 1, wherein said first melting point is at
least 200.degree. C.
10. A structure according to claim 1, wherein said elastic copolyester has
a heat of fusion of up to 6 cal/g.
11. A structure according to claim 6, wherein said cushioning layer has a
hardness such that said cushioning layer is compressed by 25% when said
cushioning layer receives a load ranging from 5 to 40 kgf.
12. A sound insulating structure found on a panel on which at least one of
a vibration and a sound is incident, said structure comprising:
a covering layer for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
5-95 wt % of a second fiber having a fineness within a range from 1.5 to 5
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total of said first and second fibers being 100 wt %, wherein
said at least one other monomer of said elastic copolyester comprises a
first glycol having a chain of at least four methylene groups.
13. A sound insulating structure found on a panel on which at least one of
a vibration and a sound is incident, said structure comprising:
a covering layer for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
5-95 wt % of a second fiber having a fineness within a range from 1.5 to 15
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total of said first and second fibers being 100 wt %, wherein
said first fiber has a second portion comprising a copolymer prepared by
copolymerizing polyethylene terephthalate and at least one monomer
selected from the group consisting of a second glycol which is different
from ethylene glycol, a dibasic acid which is different from terephthalic
acid, and an hydroxycarboxylic acid, and wherein said first and second
portions of said first fiber are bonded together and eccentrically
positioned with each other.
14. A structure according to claim 13, wherein said second glycol is one
selected from the group consisting of trimethylene glycol, tetramethylene
glycol, diethylene glycol, pentaerythritol, and bisphenol A, wherein said
dibasic acid is one selected from the group consisting of aromatic
dicarboxylic acids and fatty acid dicarboxylic acids, and wherein said
hydroxycarboxylic acid is para-hydroxybenzoic acid.
15. A sound insulating structure found on a panel on which at least one of
a vibration and a sound is incident, said structure comprising:
a covering layer for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
5-95 wt % of a second fiber having a fineness within a range from 1.5 to 15
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total of said first and second fibers being 100 wt %, wherein
said first fiber is a fiber mixture comprising a first conjugated fiber
portion having an inside which is free of a hollow space and a second
conjugated fiber portion which has an inside having a hollow space and
amounts to 20-35 wt % based on the weight of said first conjugated fiber
portion.
16. A sound insulating structure capable of being employed on a steel
automobile floor panel on which at least one of a vibration and a sound is
incident, said structure comprising:
a covering layer of carpet for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
- 95wt % of a second fiber having a fineness within a range from 1.5 to 15
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total of said first and second fibers being 100 wt %.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a sound insulating structure
for reducing an impact of vibration and/or sound which is incident on the
structure from outside, and more particularly to a sound insulating
structure that is suitable as an insulating floor carpet for an automobile
floor panel, for reducing an impact of vibration and/or sound which is
incident on the structure from the panel.
2. Description of the Prior Art
A conventional automobile insulating carpet, which is formed on an
automobile floor panel, has a cushioning or insulating soft layer for
reducing an impact of vibration and/or sound which is incident on the
panel. Hitherto, there have been proposed various materials for the
cushioning layer, such as felt, foamed urethane and nonwoven fabric made
of, for example, common polyester fibers. Such felt generally used is
prepared, for example, by at first breaking up a used cloth into fibers,
then by matting the fibers into a woollike mass, and then by subjecting
this mass to the needle punching treatment or by adding a binder such as
phenol resin to this mass and then heating this binder-added mass to
harden the same. The thus prepared felt having an apparent density from
about 0.04 to about 0.2 g/cm.sup.3 and a thickness from about 5 to about
30 mm is generally used.
An important requirement for an automobile insulating carpet is to reduce
noises such as a so-called road-noise (i.e., a noise incident on an
automobile from road). In case that the above-mentioned felt is used for
the cushioning layer, the resonance point (i.e., the point of frequency at
which the sound transmission loss becomes minimum) of this cushioning
layer falls within the road-noise frequency range (250-700 Hz). The noise
which is incident on the cushioning layer from the floor panel and within
the road-noise frequency range is much greater than the noise outside this
range. Therefore, in case of the felt, the loss factor of noise becomes
low, and thus it is not possible to obtain a sufficient damping effect and
a good sound insulation.
In view of the above-mentioned drawback of the felt, there has been
proposed a urethane foamed body as another material for the cushioning
layer. For example, Japanese Patent Unexamined First Publication
JP-A-Hei-3-176241 discloses a method of producing an automobile floor
carpet. This carpet has a foamed polyurethane layer 3, an outer
polyurethane layer 4, and nylon fibers (flock) 5 formed on the layer 4 by
electrocoating. The thus proposed foamed urethane body has a higher loss
factor and a lower noise transmission loss at the resonance point,
respectively than those of the above felt, common polyester nonwoven
fabric and the like. However, the foamed urethane body has the following
first and second drawbacks.
The first drawback of the foamed urethane body is as follows. The spring
constant of the foamed urethane body is higher than that of the felt, and
the frequency of resonance point of the foamed urethane body is also
higher than that of the felt. Therefore, in case of the foamed urethane
body, the frequency range for the effective damping which is higher than
the resonance point is narrower than that of the felt. Therefore, when the
foamed urethane body has the same thickness as that of the felt, the
former is inferior to the latter in the transmission loss within the
overall frequency range (e.g., 250-6,400 Hz). Some measures can be taken
for the purpose of obtaining a sufficient sound insulation. One of these
measures is to increase the thickness of the foamed urethane body. Another
measure is to increase the weight of a backing layer interposed between
the carpet surface layer and the cushioning layer. With this measure, the
resonance point is lowered, and thus the frequency range for the effective
damping is widened. However, these measures increase the automobile's
weight and the production cost.
The second drawback of the foamed urethane body is as follows. The cost for
producing the foamed urethane body is high. Furthermore, in the production
of the foamed urethane body, it is necessary to provide an injection step
of a polyol and an isocyanate in the form of liquid, a foaming step, and
an bonding step. Therefore, it takes a long time and it is necessary to
provide a large size facility with an exhaust apparatus, for producing the
foamed urethane body. Thus, the foamed urethane body is inferior in
productivity and economical efficiency.
As an alternative to the above-mentioned felt and foamed urethane body, a
nonwoven fabric has been proposed for the cushioning layer. Polyester
fiber is very widely used to prepare this fabric, because it is high in
Young's modulus and elastic modulus. For example, Japanese Patent
Unexamined First Publication JP-A-Hei-7-223478 discloses a nonwoven fabric
made of a polyester fiber comprising at least two types of polyester
fibers (i.e., a high-melting-point polyester fiber and a low-melting-point
polyester fiber). These at least two fibers are bonded together by heating
these fibers at a temperature within a range from the melting point of the
low-melting-point fiber to the melting point of the high-melting-point
fiber. It is mentioned in this publication that the low-melting-point
fiber preferably has a core-and-sheath structure and that the melting
point different between these fibers is preferably at least 20.degree. C.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a sound insulating
structure which is high in sound transmission loss factor within the
road-noise frequency range and particularly superior in damping effect and
sound insulation in a normal temperature range (15.degree. to 40.degree.
C.), light in weight and suitable as an automobile insulating floor
carpet.
According to the present invention, there is provided a sound insulating
structure formed on a panel on which at least one of a vibration and a
sound is incident, said structure comprising:
a covering layer for covering the panel; and
a cushioning layer for reducing an impact of the at least one of the
vibration and the sound, said cushioning layer being interposed between
said covering layer and the panel and made of a nonwoven fabric, said
nonwoven fabric comprising
5-95 wt % of a first fiber having a fineness within a range from 1.5 to 40
deniers, a first melting point, and a first portion comprising
polyethylene terephthalate, and
5-95 wt % of a second fiber having a fineness within a range from 1.5 to 15
deniers and a core portion and a sheath portion covering said core
portion, a majority of said core portion comprising polyethylene
terephthalate, said sheath portion comprising an elastic copolyester which
has a second melting point that is lower than said first melting point and
is not higher than 200.degree. C., said elastic copolyester being prepared
by copolymerizing polyethylene terephthalate and at least one other
monomer, a total weight of said first and second fibers being 100 wt %.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational sectional view showing a sound insulating
structure according to the present invention, which is formed on an
automobile floor panel;
FIG. 2 is a graph showing the relationship between log tan .delta. of the
elastic copolyester of the second fiber according to the present invention
and temperature; and
FIG. 3 is a graph showing the relationship between the sound transmission
loss of the sound insulating structures according to the present invention
and to prior art and the noise frequency, wherein the mesh portion
represents the road-noise frequency range (250-700 Hz).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, a sound insulating structure according to the present
invention will be described in detail. This sound insulating structure is
used preferably as an automobile insulating floor carpet.
As is seen from FIG. 1, a sound insulating structure 10 is, for example,
formed on an automobile floor panel 12 made of steel. The structure 10
comprises a covering layer 14 (i.e. carpet outer skin layer or carpet
proper) for covering the panel 12 and a cushioning layer 16 for reducing
an impact of at least one of a vibration and a sound which is incident on
the panel 12. It is usual that the structure 10 further has a backing
layer 18 made of a thermoplastic resin, which serves to back the covering
layer 14 and is interposed between the cushioning layer 16 and the
covering layer 14, and a fusible insulator layer 20 which is made of, for
example, an asphalt sheet and interposed between the floor panel 12 and
the cushioning layer 16.
In the invention, the cushioning layer is made of a special nonwoven
fabric. This fabric comprises 5-95 wt % (preferably 20-80 wt %) of a first
fiber (i.e., a high-melting-point fiber) and 5-95 wt % (preferably (20-80
wt %) of a second fiber (i.e., a core-and-sheath type composite or
conjugated fiber), wherein the total amount of the first and second fiber
is 100 wt %. The first fiber has a melting point which is higher than that
of the second fiber and preferably at least 200.degree. C. If the amount
of the second fiber exceeds 95 wt %, the cushioning layer becomes too hard
or stiff. With this, the cushioning layer becomes inferior in cushioning
action. Furthermore, too high proportion of the second fiber causes the
production cost increase, because the second fiber is more expensive than
the first fiber containing polyethylene terephthalate as a main component
thereof. If the amount of the second fiber is less than 5 wt %, a shaped
body of the nonwoven fabric is lowered in stability.
As is mentioned hereinabove, the first fiber includes polyethylene
terephthalate as a main component thereof. In other words, the first fiber
may be a single component fiber made of only polyethylene terephthalate or
an eccentric-type composite or conjugated fiber. This eccentric-type
conjugated fiber has first and second portions which are bonded together
and eccentrically arranged with each other in a transverse section of the
eccentric fiber. The first portion comprises polyethylene terephthalate.
The second portion comprises a copolymer prepared by copolymerizing
polyethylene terephthalate and at least one monomer selected from the
group consisting of a glycol component, a dibasic acid component, and a
hydroxycarboxylic acid. This glycol component is different from ethylene
glycol, and this dibasic acid component is different from terephthalic
acid.
Examples of the above-mentioned glycol component are trimethylene glycol,
tetramethylene glycol, diethylene glycol, pentaerythritol, and bisphenol
A. Examples of the above-mentioned dibasic acid component are aromatic
dicarboxylic acids such as isophthalic acid and naphthalenedicarboxylic
acid, fatty acid dicarboxylic acids such as glutaric acid, adipic acid and
cyclohexanedicarboxylic acid. An example of the above-mentioned
hydroxycarboxylic acid is para-hydroxybenzoic acid. It is preferable that
the thus exemplified at least one monomer for the first fiber is added in
an amount such that the above-mentioned second portion (i.e. polyethylene
terephthalate copolymer) of the first fiber has a melting point of at
least 200.degree. C. The above-mentioned eccentric-type conjugated fiber
is preferably used as the first fiber, because this eccentric-type fiber
becomes crimped by a heat treatment and thus provides the cushioning layer
which is superior in external appearance.
The eccentric-type conjugated fiber as the first fiber may be a solid-type
fiber. In other words, this fiber has an inside which is free of a hallow
space(s). However, it is preferable that this eccentric-type conjugated
fiber is a fiber mixture comprising a first conjugated fiber portion
having an inside which is free of a hollow space(s) and a second
conjugated fiber portion which has an inside having a hollow space(s) and
amounts to 20-35 wt % based on the weight of the first conjugated fiber
portion. With this, the sound insulation efficiency is greatly increased.
In the invention, the above-mentioned first and second fibers have a
fineness within a range from 1.5 to 40 deniers and a fineness within a
range from 1.5 to 15 deniers, respectively. If the fineness of the first
or second fiber is less than 1.5 deniers, the polymer discharge amount in
the melt spinning process becomes small and thus the spinning rate
decreases, or the efficiency of the carding process is lowered by thread
breakage, or the carding rate is lowered in the process of producing the
nonwoven fabric. With this, the production cost increases. On the other
hand, if the fineness of the first fiber is greater than 40 deniers, the
spinning rate is relatively lowered due to the upper limit of the polymer
discharge amount in the melt spinning process, and the difference of
fineness between the first and second fibers becomes too much and thus the
carding rate in the process of producing the nonwoven fabric is lowered,
thereby increasing the production cost. If the fineness of the second
fiber is greater than 15 deniers, the fiber number of the nonwoven fabric
and the number of the thermally fused points in the nonwoven fabric
decreases to an extent that the nonwoven fabric becomes insufficient in
resilience and that the nonwoven fabric may be in a so-called fatigue to a
great extent.
In the invention, the second fiber has a core portion and a sheath portion
covering the core portion. A majority of the core portion comprises
polyethylene terephthalate. The sheath portion comprises an elastic
copolyester which is prepared by copolymerizing polyethylene terephthalate
(as a main copolymerizing monomer) and at least one other monomer. The
elastic copolyester of the second fiber preferably has a tan .delta. of at
least 0.1 within a normal temperature range (i.e., 15.degree.-40.degree.
C.), wherein this tan .delta. is defined as a ratio of a loss elasticity
(i.e., dynamic loss, E.sub.2) of the elastic copolyester to a storage
modulus (i.e., dynamic modulus of elasticity, E.sub.1) of the elastic
copolyester. Thus, the first and second fibers are preferably bonded
together by fusing the elastic copolyester. With this, the nonwoven fiber
becomes superior in shape stability.
When the elastic copolyester of the second fiber has a tan .delta. of at
least 0.1, this copolyester has a kind of phase transition in its polymer
chain. At near the phase transition, friction between the molecular chains
becomes great. Therefore, energy of a vibration incident on the elastic
copolyester is efficiently transformed into thermal energy. With this, the
cushioning layer has a good damping effect. Thus, it is considered that a
vibration having a frequency range near the resonance point is efficiently
suppressed, thereby improving the sound transmission loss.
Polyethylene terephthalate, which is a polyester having a glycol component
having a chain of two methylene groups, has a high glass transition
temperature (Tg). Therefore, the elastic copolyester having the peak value
of tan .delta. of at least 0.1 within or near the normal temperature range
(15.degree.-40.degree. C.) can be obtained by copolymerizing polyethylene
terephthalate and the at least one other monomer which is, for example, a
glycol having a chain of at least four methylene groups. The thus prepared
copolyester provides a superior sound insulation effect under a condition
of actual use. In other words, as is shown in FIG. 2, when the elastic
copolyester having a tan .delta. of at least 0.1 within a temperature
range from 15.degree. to 40.degree. C. is used as a material for the
sheath portion of the second fiber, the nonwoven fabric of the cushioning
layer provides a superior damping effect within the normal temperature
range where the sound insulating structure is actually used. Thus, as is
shown in FIG. 3, the sound transmission loss of the sound insulation
structure of the present invention at and near the resonance point is
increased, relative to that of prior art. Furthermore, the cushioning
layer becomes stable in shape.
It is preferable that the elastic copolyester of the sheath portion is
prepared by copolymerizing polyethylene terephthalate as a main
copolymerizing monomer and the at least one other monomer and that the
elastic copolyester has a heat of fusion of up to 6 cal/g and a melting
point which is lower than the melting point of the first fiber and up to
200.degree. C., in view of the spinning process of the second fiber and
formability of the nonwoven fabric's shape. It is preferable that the
above-mentioned at least one other monomer comprises a glycol having a
chain of at least four methylene groups. Examples of the at least one
other monomer are an ester formed by the union of a glycol having a chain
of at least four methylene groups and terephthalic acid, such as
polybutylene terephthalate or polyhexamethylene terephthalate,
polycaprolactone, and a polyether as the glycol having a chain of at least
four methylene groups, such as polytetramethylene glycol.
In the invention, it is preferable that the cushioning layer has a hardness
such that the cushioning layer is compressed by 25% when it receives a
load ranging from 4 to 60 kgf. In the following, this will be referred to
as that 25% hardness of the cushioning layer is from 4 to 60 kgf. If it is
less than 4 kgf, the cushioning layer may become insufficient in
resilience. If it is greater than 60 kgf, the cushioning layer may become
too hard and may not function properly. The 25% hardness of the cushioning
layer is more preferably from 5 to 40 kgf.
In the invention, it is preferable that the cushioning layer has a
thickness within a range from 2 to 50 mm. If it is less than 2 mm, the
cushioning layer may not function properly. If it is greater than 50 mm,
the cushioning layer may become too much in volume and weight.
In the invention, it is preferable that the nonwoven fabric for the
cushioning layer has an apparent density within a range from 0.03 to 0.1
g/cm.sup.3. If it is less than 0.03 g/cm.sup.3, the cushioning layer may
become too soft, and may be easily in fatigue (i.e. permanent deformation
by pressure) and insufficient in resilience. Therefore, the cushioning
layer may not function properly. If it is more than 0.1 g/cm.sup.3, the
cushioning layer may become too hard. With this, the cushioning layer may
not have a sufficient damping capability.
The present invention will be illustrated with reference to the following
nonlimitative Examples. In the following Examples and Comparative
Examples, "part(s) by weight" will be expressed as "part(s)" for
simplicity, unless otherwise described.
EXAMPLE 1
In this example, as is shown in FIG. 1, a sound insulation structure 10
having a cushioning layer 16 of the present invention was formed on a flat
steel plate 12 as an automobile floor panel. This steel plate 12 had a
thickness of 0.8 mm and a surface density of 6.3 kg/m.sup.2. In general,
an actual automobile floor panel may not have a flat shape, but may have a
so-called bead shape to increase stiffness of the panel or may have an
irregular shape to provide a space(s) for a heater duct and/or a wiring
harness. However, a flat steel plate was used in this example for the
purpose of easily determining the 25% hardness and the sound transmission
loss. It is needless to say that a nonwoven fabric of the present
invention for the cushioning layer can be desirably shaped by a press
machine to correspond to the shape of the actual automobile floor panel
which is not flat.
In this example, a united member in which a tufted pile carpet as a
covering layer 14 and a polyethylene sheet as a backing layer 18 had been
previously bonded together was used. This tufted pile carpet had a weight
per unit are (METSUKE) of 580 g/m.sup.2. The polyethylene sheet had a
weight per unit area of 600 g/m.sup.2. As a fusible insulator layer 20, an
asphalt sheet having a thickness of 2.5 mm and a surface density of 4.0
kg/m.sup.2 was used.
As the cushioning layer 16, a nonwoven fabric which is made of polyester
and has a weight per unit area of 1,000 g/m.sup.2 at a thickness of 30 mm
was prepared as follows. At first, this nonwoven fabric was prepared by
mixing together the following three components as first and second fibers
of the present invention. That is, as the first fiber, 60 parts of
side-by-side solid-type conjugated fibers having a fineness of 2 deniers
and a length of 51 mm, and 20 parts of side-by-side hollow-type conjugated
fibers having a fineness of 6 deniers and a length of 51 mm were used. As
the second fiber, 20 parts of elastic thermally-fusible conjugated fibers
having a melting point of 170.degree. C., a fineness of 2 deniers and a
length of 51 mm was used. This second fiber was prepared so as to have a
core portion made of polyethylene terephthalate and a sheath portion made
of an elastic copolyester. This copolyester was prepared by copolymerizing
polyethylene terephthalate, polybutylene terephthalate, polycaprolactone,
and the like.
The thus prepared nonwoven fabric was heated at a temperature of
190.degree. C. in an oven so as to melt the second fiber. Then, this
fabric was shaped by a press machine to have a thickness of 20 mm and an
apparent density of 0.05 g/cm.sup.3. The thus prepared cushioning layer
had a 25% hardness of 10 kgf.
Similar to Example 1, each of the shaped nonwoven fabrics according to the
aftermentioned Examples 2-18 also had an apparent density of 0.05
g/cm.sup.3.
The united member of the covering layer 14 and the backing layer 18, the
cushioning layer 16, the fusible insulator layer 20, and the steel plate
12 were bonded together in the order shown in FIG. 1. In fact, the
polyethylene sheet as the backing layer was melted at 130.degree. C., and
under this condition the cushioning layer was placed on the polyethylene
sheet, followed by cooling, to achieve a bonding therebetween. However,
according to the present invention, a spunbonded foundation cloth or a
thermally fusible nonwoven fabric may be used to achieve the bonding
between the backing layer and the cushioning layer.
Using the thus prepared sample which is a laminate of the steel plate and
the sound insulating structure formed thereon, the following evaluation
tests were conducted, except 25% hardness test. The results are so-called
comparative results and shown in Table 1. In other words, in Table 1, "A"
means that Example was much superior to Comparative Example; "B" means
that Example was somewhat superior to Comparative Example; and "C" means
that Example was equal to Comparative Example. For example, as shown in
the first row of Table 1, the transmission loss result of Example 1 was
much superior to that of Comparative Example 1, within a frequency range
from 250 to 700 Hz, within a frequency range greater than 700 Hz, and
within an overall frequency range from 250 to 6,400; and the cushioning
effect of Example 1 was somewhat superior to that of Comparative Example
1.
1. 25% HARDNESS
In this test, only the cushioning layer was used. In fact, according to
need, a plurality of the cushioning layers were laminated to have a
thickness of at least 50 mm. A load was added to the cushioning layer so
as to compress the same by 25%, in accordance with Japanese Industrial
Standard (JIS) K 6382-1978, using a load an aluminum disk having a
diameter (.phi.) of 200 mm and a thickness of 5 mm. Upon this, the value
of this load was measured and defined as 25% hardness.
2. SOUND TRANSMISSION LOSS
The sound transmission loss was measured in accordance with Japanese
Industrial Standard (JIS) A 1416, using the sample.
3. CUSHIONING EFFECT
Using the sample, a load up to 5 kgf was added to the cushioning layer,
with the same testing machine described in JIS K 6382-1987 and an iron
disk having a diameter of 150 mm. Upon this, the amount of compression of
the cushioning layer was measured.
EXAMPLE 2
In this example, Example 1 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 70
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 10 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 8.0 kgf.
EXAMPLE 3
In this example, Example 1 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 75
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 5 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 6.0 kgf.
EXAMPLE 4
In this example, Example 1 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 40
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 40 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 25.0 kgf.
EXAMPLE 5
In this example, Example 1 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 20
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 60 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 50 kgf.
EXAMPLE 6
In this example, Example 1 was repeated except in that, as the first fiber,
60 parts of the solid-type conjugated fibers and 20 parts of the
hollow-type conjugated fibers, and as the second fiber 20 parts of elastic
thermally-fusible conjugated fibers having a fineness of 15 deniers, a
length of 51 mm and a melting point of 170.degree. C. were used. The
shaped cushioning layer had a 25% hardness of 8.0 kgf.
EXAMPLE 7
In this example, Example 6 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 70
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 10 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 6.0 kgf.
EXAMPLE 8
In this example, Example 6 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 75
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 5 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 4.0 kgf.
EXAMPLE 9
In this example, Example 6 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 40
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 40 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 20.0 kgf.
EXAMPLE 10
In this example, Example 6 was repeated except in that the mixing ratio of
the three types of fibers was modified. That is, as the first fiber, 60
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 20 parts of the elastic
thermally-fusible fibers were used. The shaped cushioning layer had a 25%
hardness of 40.0 kgf.
EXAMPLE 11
In this example, Example 1 was repeated except in that, as the first fiber,
60 parts of the solid-type conjugated fibers and 20 parts of the
hollow-type conjugated fibers, and as the second fiber 10 parts of the
elastic thermally-fusible conjugated fibers and 10 parts of nonelastic
thermally-fusible conjugated fibers having a melting point of 110.degree.
C., a fineness of 2 deniers and a length of 51 mm were used. The shaped
cushioning layer had a 25% hardness of 10.0 kgf.
EXAMPLE 12
In this example, Example 11 was repeated except in that the mixing ratio of
the four types of fibers was modified. That is, as the first fiber, 70
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 5 parts of the elastic
thermally-fusible fibers and 5 parts of the nonelastic thermally-fusible
fibers were used. The shaped cushioning layer had a 25% hardness of 8.0
kgf.
EXAMPLE 13
In this example, Example 1 was repeated except in that, as the first fiber,
60 parts of the solid-type conjugated fibers and 20 parts of the
hollow-type conjugated fibers, and as the second fiber 10 parts of elastic
thermally-fusible conjugated fibers having a melting point of 170.degree.
C., a fineness of 15 deniers and a length of 51 mm and 10 parts of
nonelastic thermally-fusible conjugated fibers having a melting point of
110.degree. C., a fineness of 15 deniers and a length of 51 mm were used.
The shaped cushioning layer had a 25% hardness of 8.0 kgf.
EXAMPLE 14
In this example, Example 13 was repeated except in that the mixing ratio of
the four types of fibers was modified. That is, as the first fiber, 40
parts of the solid-type conjugated fibers and 20 parts of the hollow-type
conjugated fibers, and as the second fiber 20 parts of the elastic
thermally-fusible fibers and 20 parts of the nonelastic thermally-fusible
fibers were used. The shaped cushioning layer had a 25% hardness of 8.0
kgf.
EXAMPLE 15
In this example, Example 1 was repeated, except in that the nonwoven fabric
was prepared so as to have a weight per unit area of 250 g/m.sup.2 at a
thickness of 10 mm and that the nonwoven fabric was shaped to have a
thickness of 5 mm. The shaped cushioning layer had a 25% hardness of 10.0
kgf.
EXAMPLE 16
In this example, Example 1 was repeated, except in that the nonwoven fabric
was prepared so as to have a weight per unit area of 500 g/m.sup.2 at a
thickness of 15 mm and that the nonwoven fabric was shaped to have a
thickness of 10 mm. The shaped cushioning layer had a 25% hardness of 10.0
kgf.
EXAMPLE 17
In this example, Example 1 was repeated, except in that the nonwoven fabric
was prepared so as to have a weight per unit area of 1,500 g/m.sup.2 at a
thickness of 45 mm and that the nonwoven fabric was shaped to have a
thickness of 30 mm. The shaped cushioning layer had a 25% hardness of 10.0
kgf.
EXAMPLE 18
In this example, Example 1 was repeated, except in that the nonwoven fabric
was prepared so as to have a weight per unit area of 2,500 g/m.sup.2 at a
thickness of 75 mm and that the nonwoven fabric was shaped to have a
thickness of 50 mm. The shaped cushioning layer had a 25% hardness of 10.0
kgf.
COMPARATIVE EXAMPLE 1
In this comparative example, a foamed urethane was used for the cushioning
layer, in place of the nonwoven fabric. This foamed urethane was prepared
as follows. A first solution consisting of 100 parts of propylene
oxide-1,2,6-hexanetriol as a polyol, 2 parts of water, one part of a
surface active agent and 0.5 parts of carbon black, and a second solution
consisting of 100 parts of tolylenediisocyanato and 0.5 parts of a
silicone oil were injected at a low pressure into a foaming mold having a
clearance of 20 mm and then were foamed therein. The thus obtained foamed
urethane sheet had a thickness of 20 mm, an apparent density of 0.06
g/cm.sup.3, and a 25% hardness of 15.0 kgf.
Similar to Comparative Example 1, each of the cushioning layers according
to the aftermentioned Comparative Examples 2-4 also had an apparent
density of 0.06 g/cm.sup.3. Each of the cushioning layers according to the
aftermentioned Comparative Examples 5-18 had an apparent density of 0.05
g/cm.sup.3.
Using the foamed urethane sheet as a cushioning layer, a laminate of the
steel plate and the sound insulating structure formed thereon was prepared
in the same manner as in Example 1, except in that the foamed urethane
sheet was bonded to the backing layer with a spray-type adhesive.
In addition to the evaluation tests of Example 1, the following test was
further conducted on the laminated (sample).
4. TRANSMISSIBILITY OF VIBRATION TO THE SOLE OF A FOOT
A load of 5 kgf equivalent to that added to the floor carpet by an average
human foot was placed on the sample, using an iron disk having a diameter
of 150 mm equivalent to the sole surface of an average human foot. Then,
under this condition, the sample was subjected to a forced vibration with
a constant force of 5N, and the transmissibility of vibration (the
vibration transmission gain) at a frequency of 30 Hz was measured. The
results are shown in the column of "Vibration Trans. to Foot" in Table 4.
Similar to the results of Table 1, the comparative results of Comparative
Example 1 as compared with another Comparative Example are shown in Table
4. In Table 4, "D" means, for example, in the first row, that Comparative
Example 1 is inferior to Comparative Example 2, with respect to the sound
transmission loss within a frequency range from 400 to 1,000 Hz. In Table
1, "Vibration Trans. to Foot" represents
COMPARATIVE EXAMPLE 2
In this comparative example, Comparative Example 1 was repeated except in
that, as a backing layer, a sheet of ethylenevinylacetate copolymer (EVA)
containing calcium carbonate as a filler was used, in place of the
polyethylene sheet having a weight per unit area of 600 g/m.sup.3. This
EVA sheet had a weight per unit area of 1,500 g/m.sup.3. The cushioning
layer had a 25% hardness of 15.0 kgf.
COMPARATIVE EXAMPLE 3
In this comparative example, a commercial felt sheet (FELTOP (tradename)
made by Howa Seni Kogyo Co.) was used. This felt sheet had a thickness of
20 mm, an apparent density of 0.06 g/cm.sup.3, and a 25% hardness of 5.0
kgf.
Using this felt sheet as a cushioning layer a laminate of the steel plate
and the sound insulating structure formed thereon was prepared in the same
manner as in Example 1.
The same evaluation tests, as those of Comparative Example 1 were conducted
on the laminate (sample).
COMPARATIVE EXAMPLE 4
In this comparative example, Comparative Example 3 was repeated except in
that, as a backing layer, the EVA sheet of Comparative Example 2 was used.
The cushioning layer had a 25% hardness of 5.0 kgf.
COMPARATIVE EXAMPLE 5
In this comparative example, Example 1 was repeated except in that 20 parts
of common nonelastic thermally-fusible conjugated fiber having a melting
point of 110.degree. C., a fineness of 2 deniers and a length of 51 mm
were used for preparing a nonwoven fabric, in place of the elastic
thermally-fusible conjugated fibers, that the nonwoven fabric was heated
up to a temperature of 175.degree. C., and that the same evaluation tests
as those in Comparative Example 1 were conducted on the sample. The
cushioning layer had a 25% hardness of 10.0 kgf.
COMPARATIVE EXAMPLE 6
In this comparative example, Comparative Example 5 was repeated except in
that 70 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 10 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 8.0 kgf.
COMPARATIVE EXAMPLE 7
In this comparative example, Comparative Example 5 was repeated except in
that 75 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 5 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 6.0 kgf.
COMPARATIVE EXAMPLE 8
In this comparative example, Comparative Example 5 was repeated except in
that 40 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 40 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 25.0 kgf.
COMPARATIVE EXAMPLE 9
In this comparative example, Comparative Example 5 was repeated except in
that 20 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 60 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 50.0 kgf.
COMPARATIVE EXAMPLE 10
In this comparative example, Comparative Example 5 was repeated except in
that 60 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 20 parts of common nonelastic
thermally-fusible conjugated fibers having a melting point of 110.degree.
C., a fineness of 15 deniers and a length of 51 mm were used. The
cushioning layer had a 25% hardness of 8.0 kgf.
COMPARATIVE EXAMPLE 11
In this comparative example, Comparative Example 10 was repeated except in
that 70 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 10 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 6.0 kgf.
COMPARATIVE EXAMPLE 12
In this comparative example, Comparative Example 10 was repeated except in
that 75 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 5 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 4.0 kgf.
COMPARATIVE EXAMPLE 13
In this comparative example, Comparative Example 10 was repeated except in
that 40 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 40 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 20.0 kgf.
COMPARATIVE EXAMPLE 14
In this comparative example, Comparative Example 10 was repeated except in
that 60 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 20 parts of the nonelastic
thermally-fusible conjugated fibers were used. The cushioning layer had a
25% hardness of 40.0 kgf.
COMPARATIVE EXAMPLE 15
In this comparative example, Comparative Example 5 was repeated except in
that 60 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 20 parts of the nonelastic
thermally-fusible conjugated fibers were used, that the nonwoven fabric
was prepared so as to have a weight per unit area of 250 g/m.sup.2 at a
thickness of 10 mm, and that the nonwoven fabric was shaped by the press
machine to have a thickness of 5 mm. The cushioning layer had a 25%
hardness of 10.0 kgf.
COMPARATIVE EXAMPLE 16
In this comparative example, Comparative Example 15 was repeated except in
that the nonwoven fabric was prepared so as to have a weight per unit area
of 500 g/m.sup.2 at a thickness of 15 mm and that the nonwoven fabric was
shaped to have a thickness of 10 mm. The cushioning layer had a 25%
hardness of 10.0 kgf.
COMPARATIVE EXAMPLE 17
In this comparative example, Comparative Example 15 was repeated except in
that the nonwoven fabric was prepared so as to have a weight per unit area
of 1,500 g/m.sup.2 at a thickness of 45 mm and that the nonwoven fabric
was shaped to have a thickness of 30 mm. The cushioning layer had a 25%
hardness of 10.0 kgf.
COMPARATIVE EXAMPLE 18
In this comparative example, Comparative Example 15 was repeated except in
that 60 parts of the solid-type conjugated fibers, 20 parts of the
hollow-type conjugated fibers, and 20 parts of the nonelastic
thermally-fusible conjugated fibers were used, that the nonwoven fabric
was prepared so as to have a weight per unit area of 2,500 g/m.sup.2 at a
thickness of 75 mm and that the nonwoven fabric was shaped to have a
thickness of 50 mm. The cushioning layer had a 25% hardness of 10.0 kgf.
As is seen from Tables 1-3, with respect to the results of the sound
transmission loss of the samples having the cushioning layers of the same
thicknesses, when the samples of Examples are compared with those of
Comparative Examples, the former was much superior to the latter, within
the road-noise range (i.e. a frequency range from 250 to 700 Hz); and the
former was superior to or at least equal to the latter, within the overall
range (i.e. a frequency range from 250 to 6,400 Hz).
As is seen from Tables 1-3, with respect to the results of the sound
transmission loss of the samples having the cushioning layers of the same
weight per unit area thereof, the samples of Examples were superior to or
at least equal to those of Comparative Examples.
As is seen from Tables 1-3, with respect to the results of the cushioning
effect test of the samples having the cushioning layers of the same
thickness, Examples 1-14 were superior to Comparative Examples 3 and 4 in
which a commercial felt was used in place of the nonwoven fabric of the
present invention.
According to the present invention, density of the cushioning layer can be
reduced by 10-30%, for obtaining the same sound insulation and the same
cushioning effect, by the nonwoven fabric of the present invention, as
those obtained by the urethane foamed body and the felt. Thus, it is
possible to make the sound insulation structure light in weight.
As is mentioned above, the sound insulating structure of the present
invention is high in sound transmission loss factor within the road-noise
frequency range and particularly superior in sound insulation at the
normal temperature. Furthermore, the sound insulating structure of the
present invention has an adequate cushioning effect and can be reduced in
weight.
TABLE 1
__________________________________________________________________________
Sound Transmission Loss
Cushioning
250-700 Hz
700 Hz <
250-6,400 Hz
Effect
__________________________________________________________________________
Example 1 relative to Com. Ex. 1
A A A B
Example 1 relative to Com. Ex. 2
C B B B
Example 1 relative to Com. Ex. 3
A A A A
Example 1 relative to Com. Ex. 4
B B A A
Example 1 relative to Com. Ex. 5
A C B B
Example 2 relative to Com. Ex. 1
A A A B
Example 2 relative to Com. Ex. 2
C B B B
Example 2 relative to Com. Ex. 3
A A A A
Example 2 relative to Com. Ex. 4
B B A A
Example 2 relative to Com. Ex. 6
A C B B
Example 3 relative to Com. Ex. 1
A A A B
Example 3 relative to Com. Ex. 2
C B B B
Example 3 relative to Com. Ex. 3
A A A A
Example 3 relative to Com. Ex. 4
B B A A
Example 3 relative to Com. Ex. 7
A C B B
Example 4 relative to Com. Ex. 1
A A A B
Example 4 relative to Com. Ex. 2
C B B B
Example 4 relative to Com. Ex. 3
A A A A
Example 4 relative to Com. Ex. 4
B B A A
Example 4 relative to Com. Ex. 8
A C B B
Example 5 relative to Com. Ex. 1
A A A B
Example 5 relative to Com. Ex. 2
C B B B
Example 5 relative to Com. Ex. 3
A A A A
Example 5 relative to Com. Ex. 4
B B A A
Example 5 relative to Com. Ex. 9
A C B B
Example 6 relative to Com. Ex. 1
A A A B
Example 6 relative to Com. Ex. 2
C B B B
Example 6 relative to Com. Ex. 3
A A A A
Example 6 relative to Com. Ex. 4
B B A A
Example 6 relative to Com. Ex. 10
A C B B
__________________________________________________________________________
TABLE 2
__________________________________________________________________________
Sound Transmission Loss
Cushioning
250-700 Hz
700 Hz <
250-6,400 Hz
Effect
__________________________________________________________________________
Example 7 relative to Com. Ex. 1
A A A C
Example 7 relative to Com. Ex. 2
C B B B
Example 7 relative to Com. Ex. 3
A A A A
Example 7 relative to Com. Ex. 4
B B A A
Example 7 relative to Com. Ex. 11
A C B B
Example 8 relative to Com. Ex. 1
A A A B
Example 8 relative to Com. Ex. 2
C B B B
Example 8 relative to Com. Ex. 3
A A A A
Example 8 relative to Com. Ex. 4
B B A A
Example 8 relative to Com. Ex. 12
A C B B
Example 9 relative to Com. Ex. 1
A A A C
Example 9 relative to Com. Ex. 2
C B B B
Example 9 relative to Com. Ex. 3
A A A A
Example 9 relative to Com. Ex. 4
B B A A
Example 9 relative to Com. Ex. 13
A C B B
Example 10 relative to Com. Ex. 1
A A A B
Example 10 relative to Com. Ex. 2
C B B B
Example 10 relative to Com. Ex. 3
A A A A
Example 10 relative to Com. Ex. 4
B B A A
Example 10 relative to Com. Ex. 14
A C B B
Example 11 relative to Com. Ex. 1
A A A B
Example 11 relative to Com. Ex. 2
C B B B
Example 11 relative to Com. Ex. 3
A A A A
Example 11 relative to Com. Ex. 4
B B A A
Example 11 relative to Com. Ex. 5
A C B B
Example 12 relative to Com. Ex. 1
A A A B
Example 12 relative to Com. Ex. 2
C B B B
Example 12 relative to Com. Ex. 3
A A A A
Example 12 relative to Com. Ex. 4
B B A A
Example 12 relative to Com. Ex. 6
A C B B
__________________________________________________________________________
TABLE 3
__________________________________________________________________________
Sound Transmission Loss
Cushioning
250-700 Hz
700 Hz <
250-6,400 Hz
Effect
__________________________________________________________________________
Example 13 relative to Com. Ex. 1
A A A B
Example 13 relative to Com. Ex. 2
C B B B
Example 13 relative to Com. Ex. 3
A A A A
Example 13 relative to Com. Ex. 4
B B A A
Example 13 relative to Com. Ex. 10
A C B B
Example 14 relative to Com. Ex. 1
A A A B
Example 14 relative to Com. Ex. 2
C B B B
Example 14 relative to Com. Ex. 3
A A A A
Example 14 relative to Com. Ex. 4
B B A A
Example 14 relative to Com. Ex. 13
A C B B
Example 15 relative to Com. Ex. 15
A C B B
Example 16 relative to Com. Ex. 16
A C B B
Example 17 relative to Com. Ex. 17
A C B B
Example 18 relative to Com. Ex. 18
A C B B
__________________________________________________________________________
TABLE 4
__________________________________________________________________________
Sound Transmission Loss
Cushioning
Vibration
400-1,000 Hz
1,000 Hz <
250-6,400 Hz
Effect
Trans. to Foot
__________________________________________________________________________
Com. Ex. 1 relative to Com. Ex. 2
D D D C C
Com. Ex. 1 relative to Com. Ex. 3
D C C A A
Com. Ex. 1 relative to Com. Ex. 4
D D D A A
Com. Ex. 2 relative to Com. Ex. 1
A A A C C
Com. Ex. 2 relative to Com. Ex. 3
B A B A A
Com. Ex. 2 relative to Com. Ex. 4
D C C A A
Com. Ex. 3 relative to Com. Ex. 1
B C C D D
Com. Ex. 3 relative to Com. Ex. 2
D D D D D
Com. Ex. 3 relative to Com. Ex. 4
D D D C C
Com. Ex. 4 relative to Com. Ex. 1
A A B D D
Com. Ex. 4 relative to Com. Ex. 2
A C B D D
Com. Ex. 4 relative to Com. Ex. 3
A A A C C
Com. Ex. 5 relative to Com. Ex. 1
B A B B B
Com. Ex. 5 relative to Com. Ex. 2
D B C B B
Com. Ex. 5 relative to Com. Ex. 3
A A A A A
Com. Ex. 5 relative to Com. Ex. 4
C B B A A
Com. Ex. 6 relative to Com. Ex. 1
B A B B B
Com. Ex. 6 relative to Com. Ex. 2
D B C B B
Com. Ex. 6 relative to Com. Ex. 3
A A A A A
Com. Ex. 6 relative to Com. Ex. 4
C B B A A
Com. Ex. 7 relative to Com. Ex. 1
B A B B B
Com. Ex. 7 relative to Com. Ex. 2
D B C B B
Com. Ex. 7 relative to Com. Ex. 3
A A A A A
Com. Ex. 7 relative to Com. Ex. 4
C B B A A
Com. Ex. 8 relative to Com. Ex. 1
B A B B B
Com. Ex. 8 relative to Com. Ex. 2
D B C B B
Com. Ex. 8 relative to Com. Ex. 3
A A A A A
Com. Ex. 8 relative to Com. Ex. 4
C B B A A
__________________________________________________________________________
TABLE 5
__________________________________________________________________________
Sound Transmission Loss
Cushioning
Vibration
400-1,000 Hz
1,000 Hz <
250-6,400 Hz
Effect
Trans. to Foot
__________________________________________________________________________
Com. Ex. 9 relative to Com. Ex. 1
B A B B B
Com. Ex. 9 relative to Com. Ex. 2
D B C B B
Com. Ex. 9 relative to Com. Ex. 3
A A A A A
Com. Ex. 9 relative to Com. Ex. 4
C B B A A
Com. Ex. 10 relative to Com. Ex. 1
B A B B B
Com. Ex. 10 relative to Com. Ex. 2
D B C B B
Com. Ex. 10 relative to Com. Ex. 3
A A A A A
Com. Ex. 10 relative to Com. Ex. 4
C B B A A
Com. Ex. 11 relative to Com. Ex. 1
B A B B B
Com. Ex. 11 relative to Com. Ex. 2
D B C B B
Com. Ex. 11 relative to Com. Ex. 3
A A A A A
Com. Ex. 11 relative to Com. Ex. 4
C B B A A
Com. Ex. 12 relative to Com. Ex. 1
B A B B C
Com. Ex. 12 relative to Com. Ex. 2
D B C B C
Com. Ex. 12 relative to Com. Ex. 3
A A A A A
Com. Ex. 12 relative to Com. Ex. 4
C B B A A
Com. Ex. 13 relative to Com. Ex. 1
B A B B B
Com. Ex. 13 relative to Com. Ex. 2
D B C B B
Com. Ex. 13 relative to Com. Ex. 3
A A A A A
Com. Ex. 13 relative to Com. Ex. 4
C B B A A
Com. Ex. 14 relative to Com. Ex. 1
B A B B B
Com. Ex. 14 relative to Com. Ex. 2
D B C B B
Com. Ex. 14 relative to Com. Ex. 3
A A A A A
Com. Ex. 14 relative to Com. Ex. 4
C B B A A
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